News Corp. CEO Rupert Murdoch and his son James are in the hot seat this week at a high-profile public inquiry in the U.K. about phone hacking by News Corp's British newspapers. NBC's Stephanie Gosk reports.

By Alastair Jamieson, msnbc.com and Stephanie Gosk, NBC News

Updated 12:31 p.m. ET: LONDON - Rupert Murdoch was grilled at a high-profile public inquiry into media ethics on Wednesday, rejecting charges that he used his powerful British newspapers to influence politicians for the benefit of his business interests.

He rejected accusations that he used his media empire to play puppet master to a succession of British prime ministers, electrifying a media inquiry that has shaken the government and unnerved much of the establishment.

What began with cases of voicemail interception at one of his U.K. tabloid newspapers has turned into a critique of how the British media operates -- and a deep look at the influence Murdochs's corporation, News Corp., has had on the highest echelons of government.

Prime Minister David Cameron appointed judge Brian Leveson to examine Britain's press standards after journalists at Murdoch's weekly News of the World tabloid admitted hacking into phones on a massive scale to generate exclusives.

After taking an oath, Murdoch said he was keen to put straight some myths about him.

"I have never asked a prime minister for anything," Murdoch said calmly when asked about his links to former Prime Minister Margaret Thatcher, one of his favorite British leaders. Murdoch also claimed he “never asked Tony Blair for anything” despite meeting that former Prime Minister 40 times in person.

Some politicians had expected the 81-year-old - courted by prime ministers and presidents for decades - to come out fighting, having been on the back foot for almost a year over a newspaper phone hacking scandal that has convulsed his empire.

Leon Neal / AFP - Getty Images

News Corp chief executive Rupert Murdoch and his wife Wendi Deng leave their London home on Wednesday.

But Murdoch appeared calm and laconic, at times provoking chuckles from some of the 70 lawyers, family members and journalists packed into the Victorian gothic courtroom when he cracked jokes about the destruction of unions and a disgraced former British minister who lied in court.

The man who has for years portrayed himself as an underdog, said he had simply tried to shine a light on the country on the behalf of the working classes.

"I think that it is fair when people hold themselves up as iconic figures, or great actors, that they be looked at," he said. "I don't think they are entitled to the same privacy as the ordinary man on the street."

But he admitted that his opinion had been carried by newspaper The Sun, one of his favorites for years. "I'm not good at holding my tongue," he said. "If you want to judge my thinking, look at the Sun."

'Declare war' on News Corp.?He also shed some light on recent British political history, saying that then Prime Minister Gordon Brown had reacted to the news that the Sun newspaper would be withdrawing its support for the Labour party by threatening to "declare war" on News Corp. "I did not think he was in a very balanced state of mind," Murdoch said.

Mr Brown later said Murdoch's claim was "wholly wrong".

Asked if as reported he had initially found Cameron to be lightweight, Murdoch replied: "No. Not then." He had also not found it strange when Cameron took time out of his own private holiday to meet him on a yacht off a Greek island in 2008.

"I've explained that politicians go out of their way to impress people in the press," he said.

James Murdoch was at the Leveson inquiry on Tuesday, claiming he didn't know about phone-hacking at News Corp's UK newspapers. ITV's Juliet Bremner reports.

He played down the influence of his newspapers on the outcome of elections, saying: "It is only natural for politicians to reach out to editors and sometimes proprietors, if they are available, to explain what they are doing and hoping that it makes an impression. But I was only one of several."

Prosecutor Robert Jay asked: "Are you saying that you are completely oblivious to the impact of election outcomes on your commercial interests? Murdoch replied: "Absolutely. I never let my commercial interests, whatever they are, enter into any consideration of elections."

Murdoch candidly described one of his own newspapers' most infamous front page headlines as "tasteless". After the Conservatives scraped a narrow win in the 1992 general election, The Sun, which had backed the party, declared: 'IT WAS THE SUN WOT WON IT'. "We don't have that kind of influence," Murdoch insisted, adding that he had been angry with then editor Kelvin McKenzie about the headline.

He said the notion of his influence over politicians was "a myth", adding: "How I treat Mayor Bloomberg in New York - sends him crazy. But, we support him every time he runs for re-election."

Rupert Murdoch will give further testimony on Thursday, when he is expected to face questions about phone hacking.

'Appalled'However, in a written submission yesterday he said he was "appalled" to discover that lawyers for his newspaper The Times had misled the inquiry by earlier claiming claiming the title had never been involved in hacking, the Daily Telegraph reported.

It later emerged a Times reporter had hacked into a policeman’s email account. Murdoch said in his witness statement to the inquiry on Wednesday: “I am appalled that the lawyer misled the court and disappointed that the editor published the story.”

This is his second public grilling on the issue. The first was before parliament last July, supported by his son James and protected by his wife. This time he was alone -- although his other son, Lachlan, and wife Wendi Deng were watching from a distance in the public gallery.

Shareholders in News Corp. will be looking very closely at his performance. His task at the inquiry is to defend the world’s second largest media company – and, with it, his own reputation.

Evidence emerged last July that suggested multiple reporters at News of the World hacked into the voicemails of celebrities, the royal family and even a murdered young girl. Those revelations convulsed Murdoch's media empire and provoked a wave of public anger.

More than 100 lawsuits have been filed in the U.K., and a lawyer for hacking victims intends says he intends to file three more in the U.S. Three ongoing criminal cases in Britain have resulted in a series of arrests.

Leveson Inquiry / AFP - Getty Images

News Corp executive chairman James Murdoch swearing an oath holding a bible before giving evidence at the Leveson Inquiry into press standards at the High Court in London on Tuesday.

Critics allege The Sun, endorsed Cameron during the 2010 election in return for support of News Corp’s deal to buy full control of broadcaster BskyB.

Murdoch was the first newspaper boss to visit Cameron after he won the election -- entering via the back door -- and politicians from all parties have lived in fear for decades of his newspapers and what they might reveal about their personal lives.

U.S.-based News Corp, owner of Fox Television and the Wall Street Journal, eventually pulled its bid to buy the 61 percent of satellite broadcaster BSkyB that it did not already own amid the intense political and public pressure over phone hacking.

Opposition politician Chris Bryant, who accepted damages from Murdoch's British newspaper group after the paper admitted hacking his phone, said the media mogul had dominated the political landscape for decades.

“You have only got to watch Rupert Murdoch's staff with him to see how his air of casual violence intimidates people," he told Reuters. "His presence in the British political scene has similarly intimidated people by offering favor to some and fear to all."

Murdoch's relations with prime ministers goes back decades: papers released this year showed that he held a secret meeting with then-Prime Minister Margaret Thatcher in 1981 to secure his acquisition of the Times of London.

Tony Blair was godfather to one of Murdoch's daughters, Gordon Brown was a personal friend of the Australian-born businessman and Cameron employed as his personal spokesman a former Murdoch editor who was himself implicated in the hacking scandal.

During a parliamentary hearing last year, memorable for the actions of a protester who hit Murdoch in the face with a foam pie, he sat alongside James and spoke often in monosyllables but on occasion hit the table with his fist in frustration at the line of questioning.

Chiara Francavilla, NBC News in London, and Reuters contributed to this report.